The instant invention relates to the machine tool industry and, more particularly, to a coupling construction which is operable in a workholding system for securing a workpiece at a work station and to a clamp for securing receiver and carrier portions of the coupling in a coupled position.
It has been found that couplings of the type set forth in copending U.S. patent application Ser. No. 647,715, filed on Sept. 4, 1984 which issued as U.S. Pat. No. 4,575,062 on Mar. 11, 1986, can be effectively utilized in workholding systems for securing workpieces at sequential work stations and that they represent significant improvements in the art relating to workholding systems. In this regard, the coupling construction disclosed in application Ser. No. 647,715 comprises receiver and carrier portions which are receivable in a coupled position and which are particularly adapted for construction of the coupling with a reduced axial dimension, and a plurality of clamps for securing the receiver and the carrier portions of the coupling in the coupled position. For use and operation of a coupling of this type in a workholding system, a different receiver is secured at each of a plurality of sequential work stations and a workpiece which is to be sequentially machined at the work stations is secured on a carrier. The carrier and the workpiece are then sequentially secured to the different receivers at the different work stations for the performance of machining operations on the workpiece. It has been found that a coupling of this type can be effectively utilized for orienting a workpiece at sequential work stations and that because it is operative with a high degree of precision, many of the lengthy and time-consuming set up and adjustment procedures which have heretofore been required each time a workpiece is installed at a different work station can be eliminated. However, because it is desirable to clamp the receiver and carrier portions of a coupling of this type in a coupled position with extremely high clamping pressures in order to precisely and accurately maintain them in proper orientation, the clamps of a coupling of this type must be durable and easily actuatable to apply high clamping pressures to the receiver and carrier portions of the coupling to secure them in a coupled position.
The instant invention provides an improved coupling construction and an improved clamp for use in the coupling construction, wherein the clamp is effectively operable for applying extremely high clamping pressures to the receiver and carrier portions of the coupling in order to effectively maintain them in a coupled position. The clamp construction of the instant invention comprises a clamp body, a clamping member mounted on the clamp body, a movable or slide member mounted on the clamp body so that it is movable towards the clamping member, spring means actuatable for biasing the movable member toward the clamping member when an element to be clamped is received in engagement between the clamping member and the movable member, and means for actuating the spring means. The means for actuating the spring means comprises a toggle member and first, second, and preferably third knuckle and socket means which cooperate to mount the toggle member so that it is pivotable to actuate the spring means and so that the spring means communicates with the movable member through the first, second and third knuckle and socket means and the toggle member. In the preferred embodiment of the clamp, the first knuckle and socket means comprises a first knuckle element which is formed on an enlarged end of the toggle member, and a socket which is formed in the movable member and in which the first knuckle element is received, and the second knuckle and socket means comprises a second knuckle element which is formed on the opposite side of the toggle member end from the first knuckle element, and a pivot member having a second socket formed therein, the second knuckle element being received in the second socket. The third knuckle and socket means preferably comprises a third knuckle element formed on a retainer ring of the spring means and a third socket which is formed in the pivot element and in which the third knuckle element is received. The clamp is operable by pivoting the toggle member to move the movable member toward the clamping member until an object which is received between the movable and clamping members prevents further movement of the movable member towards the clamping member. Thereafter, when the toggle member is further pivoted to urge the movable member toward the clamping member, it operates to actuate the spring means to bias the movable member toward the clamping member. Throughout this operation, however, the elements of the clamp which are operative for providing communication between the spring means and the movable member, operate through the first, second and third knuckle and socket means for first moving the movable member toward the clamping member and for thereafter transmitting forces from the spring means to the movable member. Accordingly, the first, second and third knuckle and socket means provide a durable and effective means for transmitting forces from the spring means to the movable member. Specifically, because the knuckle elements rotate in their respective sockets as the toggle member is pivoted to urge the movable member towards the clamping member, the toggle member can be easily and reliably pivoted to actuate the spring means without causing excessive wear in the clamp.
Accordingly, because of the efficient and reliable manner in which the clamp of the instant invention is operable, it provides substantial advantages in the coupling construction of the instant invention. In this regard, the coupling construction of the instant invention comprises a receiver and a carrier which are securable in a coupled position, and at least one of the clamps of the instant invention which is operable for securing the receiver and the carrier in the coupled position. Preferably, the receiver and the carrier are formed so that they cooperate to define an open interior area in the coupling, and the coupling comprises a plurality of the clamps which are disposed in the open interior area so that they are engageable with the receiver and the carrier at a plurality of spaced points to firmly secure them in a coupled position. Accordingly, the clamps are operative for securing the receiver and the carrier in a coupled position, and the manner in which the clamps operate makes them effective and reliable for performing this function. Specifically, the manner in which the clamps operate makes them easily actuatable for applying high clamping pressures to the receiver and the carrier to positively secure them in the coupled position. In addition to the substantial improvements in the coupling provided by the clamp of the instant invention, the preferred embodiment of the coupling construction further comprises means for aligning the receiver and the carrier before the clamps are operated to secure the receiver and the carrier together, and a cam drive means which is operable from the exterior of the coupling for pivoting the toggle members of the clamps to actuate the respective spring means thereof. These features make the coupling construction of the instant invention even easier and faster to operate and hence they also represent significant improvement in the coupling. Accordingly, it is seen that the instant invention provides substantial improvements over the coupling construction and clamp disclosed in copending application Ser. No. 647,715, and that these improvements make the coupling and clamp of the instant invention operable with increased effectiveness in a workholding system for securing workpieces at sequential work stations. More specifically, these features increase the effectiveness of the coupling for use in both rotating and stationary machining applications and they further facilitate the transfer of workpieces from cubical machining settings to cylindrical machining settings.
It is, therefore, a primary object of the instant invention to provide an improved coupling construction for use in a workholding system.
Another object of the instant invention is to provide an improved clamp for use in a coupling construction, wherein the coupling construction is operable in a workholding system.
An even further object of the instant invention is to provide a clamp for use in a coupling construction, wherein the clamp is effectively operable for biasing receiver and carrier portions of the coupling together with high clamping pressures.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.